In the year 2143, Earth is plagued by a mysterious phenomenon known as "puppetization." Once a living being or machine falls victim to this, they lose their consciousness and become highly aggressive... As the number of "puppets" on the surface increases, countries are thrown into chaos, and humans are forced to fight against them. With the puppets relentlessly converting both organic and mechanical entities, humanity is pushed to the brink of extinction. 80% of the land is now under puppet control, leaving the world in ruins.

In this dire situation, traditional weapons prove ineffective against the puppets. To launch a counter-attack, humans must resist being controlled like puppets themselves. Thus, the "Artery Gear Project" is initiated.

By augmenting the human body with prosthetics, individuals gain resistance against puppetization. These girls, known as "Artery Gears," undergo training and are equipped with various weapons to take on the task of eliminating puppets.

The war against the puppets begins, but on the other hand, the two remaining human factions, the "Alliance Front" and "Otoruna," lack trust and fail to form a comprehensive strategic cooperation...

To eliminate suspicion and completely eradicate the puppets, a joint force called "The Bond" is established. Both the Alliance Front and Otoruna appoint a new commander whom they can trust. Will this commander bring an end to the seemingly hopeless puppet war? Or are humans merely a fleeting moment in the history of this planet?